An excellent post on the evolutionary function of reasoning - it is to win arguments, rather than find truth.
- "However, for communication to be possible, listeners have to have ways to discriminate reliable, trustworthy information from potentially dangerous information—otherwise speakers would be wont to abuse them through lies and deception. One way listeners and speakers can improve the reliability of communication is through arguments. The speaker gives a reason to accept a given conclusion. The listener can then evaluate this reason to decide whether she should accept the conclusion." (Richard Rorty on reason as a "clever way of talking about things" - check)
- "When people reason alone, there will often be nothing to hold their confirmation bias in check. This might lead to distortions of their beliefs." (C.S. Peirce on knowledge generation as a social endeavor - check)
- "Proactively used reasoning also favors decisions that are easy to justify but not necessarily better. In all these instances traditionally described as failures or ﬂaws, reasoning does exactly what can be expected of an argumentative device: Look for arguments that support a given conclusion, and, ceteris paribus, favor conclusions for which arguments can be found." (John Maynard Keynes on remorseless logicians ending up in Bedlam - check)
Why anyone would want to base either their epistemology or their methodology on reason is beyond me. At best reasoning is just an internally consistent language with no guarantee of correspondence with the real world. At worst it's not even internally consistent because we don't do it well enough. It's a tool and a useful one. Internally consistent and intelligible languages and grammars are important for thinking things through, after all. But it's not a foundation.